Present fluorescent fixtures utilize ballasts which are positioned within a ballast case comprised of a flat base portion and a cover portion secured thereto. The conventional ballasts normally include a core and coil subassembly mounted on one end of the base portion with the terminations of the coils extending therefrom. The core and coil assembly is preferably positioned in the case so that the assembly is spaced from the top surface of the case and the sides thereof for heat and sound insulation purposes. During the manufacture of the ballast, elongated flexible external leads are electrically connected to predetermined coil terminations. The total subassembly may then be encased in an asphalt silica sand potting compound. The base portion is then positioned over the ballast components and secured to the case portion with the flexible leads extending outwardly from the case. These discrete external leads are subsequently electrically connected to leads or terminals in the appropriate lamp holders.
While the above described fixtures are generally satisfactory in operation, they do suffer several drawbacks or disadvantages. One disadvantage of prior art fixtures is that different lamp manufacturers require ballasts having leads of different lengths, thereby requiring the ballast manufacturer to produce, and inventory, ballasts having various lead lengths. Further, each individual manufacturer may require various length leads to accommodate various lamp fixtures.
A further disadvantage of the prior art ballasts and fluorescent fixtures is that the external leads, which extend from the ballast, often interfere with other assembly operations. Because the location of the lamp holders and ballast varies in different fixtures, it is necessary to connect all of the discrete leads after the lamp holders have been installed on the fixture. The installation of lamp holders and ballast, and the subsequent connection of the discrete leads to the various components, is inefficient and time consuming for the manufacturer.
One form of a ballast which overcomes several of the problems associated with ballasts having discrete leads, is disclosed in U.S. patent application Ser. No. 257,538, filed Oct. 14, 1988, entitled "An Improved Ballast", the disclosure of which is incorporated herein by reference. The ballast of the co-pending application may be described as a "lead-less ballast" in view of the fact that no discrete conductors extend from the ballast. Rather, the core and coil subassembly is mounted in one end of a case, and has terminal pins extending from one end of the core and coil subassembly which are connected to an electrical connector means. The ballast case is provided with an access opening formed therein to facilitate the extension or insertion of one end of a wiring harness therethrough which is electrically connected to the electrical connector to complete the desired wiring circuit.
Another form of leadless ballast is disclosed in the co-pending application entitled "Improved End Connector for a Ballast", filed simultaneously herewith, the disclosure of which is incorporated herein by reference. While the improved ballast of co-pending application Ser. No. 257,538 created a lead-less ballast, the wiring harness was connected to the ballast through an opening in the top of the ballast case. The new "end-connector" ballast avoids the need for long conductors to a wiring harness because the harness is connected to the ballast adjacent the ballast case base, so that the wires do not project outwardly into the lamp fixture.
It is therefore a general object of the present invention to provide an improved fluorescent lamp fixture having electrical conductors mounted therein between the lamp holders and electrical connections to reduce discrete leads.
Another object of the present invention is to provide a fluorescent lamp fixture which greatly reduces the time and labor necessary to assemble the fixture.
A further object of the present invention is to provide a lamp fixture with integral lamp holders.
A further object of the present invention is to provide a fluorescent lamp fixture which is economical to manufacture.
Yet another object is to provide a fluorescent lamp fixture which allows for the automated assembly of the fixture and ballast.
These and other objects of the present invention will be apparent to those skilled in the art.